âIâm comparing it to leaving school,â says Matthew Lewis, aka mild-mannered Neville Longbottom, the unlikely hero of Harry Potter And The Deathly Hallows: Part 2. âOnly when we left school, we didnât leave in front of 10,000 people in the middle of London. Itâs an odd prospect.â And an emotional one.

Tears were shed off â and on âÂ the red carpet at Thursdayâs British premiere of the final Harry Potter movie because itâs not just fans who are saying goodbye to Hogwarts. Metro went to meet its young cast, who are finally graduating from the cosy confines of the highest-grossing film franchise of all time and wondering: what next?

âItâs been a real mixture of feelings since we finished,â admits Rupert Grint, aka Harryâs best friend, Ron Weasley, the only cast member to look younger (and no cooler) in real life. âI remember looking forward to it. Itâs been such a huge commitment and the thought of some freedom seemed really needed.

âBut actually, the last day was really sad,â Grint adds, his big, blue eyes and white eyelashes making him look like a downcast pet gerbil in need of a cuddle. âI kind of underestimated how important these ten years have really been. And since weâve finished, Iâve kind of felt lost without it. I had all these plans, like getting tattoos and changing my hairstyle, stuff we werenât allowed to do during production. Then, as soon as I had that freedom, I thought:Â âNah, I donât want to do that.ââ

Other cast members were notÂ so conservative. âSkiing, bungee jumping, sky-diving â Iâve tickedÂ all those off,â laughs Tom Felton , unrecognisable as Harryâs rival, Draco Malfoy, thanks to his low-cut Jude Law-style T-shirt and new tan, gained while shooting upcoming Hollywood blockbuster Rise Of The Planet Of The Apes. âIt is a bit like leaving school,â he says. âAt first I was terrified of being thrust into the big, bad world but itâs something that excites me now.â

And despite losing out to Daniel Radcliffe in the original auditions, Felton has nothing but praise for his on-screen nemesis. âPeople ask if Iâm jealous I didnât get to play Harry but God knows I could never have done what Danâs done,â says Felton. âHeâs exceptionally polite, heâs always kind and Iâve never seen him lose his temper or raise his voice.â

âI think it really goes to show that you can be an actor with that amount of fame and be followed everywhere, and you donât have to be a knobhead,â chimes in Lewis, who, with his Leeds lad stubble, Ray-Bans and styled quiff, is similarly unrecognisable as Neville.

Head boy Radcliffe is absent today âdue to his Broadway scheduleâ (heâs starring in a musical in New York despite never having sung or danced on stage before). Unofficial head girl Emma Watson, now studying at Brown University in between fashion shoots for the likes of Vogue, is here, though, and is similarly respected by cast and crew alike.

âSheâs not only a hugely talented actress, she is super bright,â says David Heyman, who first happened upon an unpublished Harry Potter manuscript in 1997 and has since produced every movie. âEmma supposedly got the highest grade in her English A level in the entire country. She got into Oxbridge and she could have gone to Harvard.â

Thatâs an achievement Watson herself credits to her Potter character, super swot Hermione. âI think Hermione made me work harder just as a result of comparing myself to her every day,â she enthuses.

âIn a way, I guess Iâm headmaster,â Heyman muses. Of course, he acknowledges, teenagers will be teenagers. âThere was an article in GQ magazine recently about how Dan said heâd âstopped drinkingâ after he was drinking a lot on the film. But at 18 years old, what do you do? I was partying like a demon.

âYes, they party, they drink, they have a good time, they sleep with people, all the natural things you do at that age. But if you consider the pressure thatâs been on them, I feel really proud that they have turned out as well as they have.â

And, Heyman admits, school really is out. âThere wonât be another Harry Potter book,â confirms this close confidante of JK Rowling. âI mean, whatâs it going to be? Harry Goes To Business School?â

Harry Potter And The Deathly Hallows: Part 2 is in cinemas this week and it will be reviewed in MetroLife on Friday.Pictures: Check out the cast at the New York premiere below: